Lifting jack



June 5 1928 T. c. POMEROY ET AL LIFTING JACK s 2 s s n O. O E m WE M L Mw. www M E m o N n w. M y Mw. 2 www* .nbhvb m Nb wh wm,

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Patented June 5, 1928.

V A 1,612,2s1- UNITED STATES PATENT: oFFlCl..l

' 'rnuo'rrnr` c. romiinov, or MINNEAPOLIS, AND cannn JoHNsoN, or s'r.PAUL, MIN- NESOTA, assumons or oNEfrHIRn 'ro JEREMIAH E. MADDEN, orcnicaeo, ILLI- NOIS.

LIFTING JACK.

Application led August 28, 1924. Serial No. 734,730.

'I` his invention relates to new and useful lmprovements'in liftingJacks such as are commonly employed for-lifting the wheels for liftingheavy loads such as a portion of a locomotive or railroad coach or car.The operating means of the jack preferably c onsists of a jointed handlehaving a relatively small vpump-rod reciprocally mounted .in a sectionthereof, which, when actuated, functions to move vthe fluid within thejack during the lifting operation thereof; The operating handle ispreferably connected to the lifting head of the jack in order tosimplify -ing and closing of y manipulationA of the 'oper' constructionand to provide a simple and convenient means for actuating the valvemechanism mounted therein. The novel valve mechanism is soconstructedthat, when the'handle of the jack is in folded inoperative position allof the valve ports will be closed to prevent leakage of oil from thejack when transported from place to place and, as soon as the handle isunfolded or extended, the valve ports opened so that the jack may beoperated to lift a load. When it isdesired' to lower the jack, a slightoscillation or lowering of thevhandle will permit the .fluid to by--pass from beneath the pistonthrough the head to the upper side thereofor into the hollow plunger, thereby causing the head and plunger togradually descend or if desired the load may be held on the jack byslightly raising the handle to close the lay-pass.4 An air vent isprovided in the head of the jack to facilitate pumping the fluid fromand to the interior of the plunger, through the head to the under sideof the plunger. The openthis vent is also controlled should the jackaccidentally'or inadvertently be overloaded. Y l,

duty liftwill be automatically The object therefore of the invention isto provide an improved jack.

A further and more specific object of the.v

invention is .to provide a hydraulic jack of simple and inexpensiveconstruction which may readily becarried from place toplace, and iscapable of operation with a minimum amount of energy and at the sametime will be positive and eiiicient in its performance.

Other objects of. thel invention will appearv 'from vthe followingdescription and the accompanying drawing-s and will be pointed out inthe annexed claims.

' In the drawings there is disclosed a structure designed to carry out'the various objects of the invention but it`is to be understood thatthe invention is not confined to the exact features shown, as variouschanges may be made within the scope of the claims which t follow. y

In the drawings: y

Figure 1 is a verticalsectional view of the improved jack; Y

Figure 2 is a plan -view of Figure 1, showing the handle extended ,andpartially in sec tion, and also showlng the jack with the liftingbracket removed;

Figure 3 is a horizontal sectional view on the line 3--3 of Figure 1with the lifting bracket removed showing the preferred manner ofconnecting the operating handle to the head;

Figure 4 is a detail sectional view on the line 4-4 of Figure 3, showingthe means provided for by-passin the fluid from beneath the plunger ento the upper side thereof as when lowering the plunger;

Figure 5 is a similar view on the line 5-5 of Figure 3, showing the airvent communie. eating with the upper portion of the plung- QI'.; .i

Figure 6 is an enlarged detail sectional view showing the preferred formof packing employed betweenthe upper end of the cylinder and the.,plunger, and also showing the means provided for limiting the upward lmovement of the plunger;

Fi ure 7 is a detail sectional view on the line -7 of Figure 2; 4

`Figure 8 is an enlarged detail sectional view on the line 8-8 of Figure1;

- Fi ure-9 is a horizontal sectional view on the ine 9-9 of Fi` re '1,showing only the Vlifting head an the tapered valve u means such as thethreads 22.

mounted therein, the valve being shown in the cylinder, and as shown inFigure 1 thev lower end of this sleeve is closed by means of ashouldered disc'or plate 14. A packing cup 15 of suitable material isseated against this plate and is tensionably held in'eontact with thewalls of the cylinder by means of a .cup-shaped retaining member 16mounted therein. A washer 17 is seated against the Vmember 16andthis'washer is apertured to receive-the threaded ends of an intake tube18 and a discharge tube 19, arranged in f spaced parallel relationlWithin the hollow plunger 13. The upper ends of thesetubes are securedto ya lifting head 21 by suitable The lifting head 21 is preferablyprovided. with an annular shoulder 23, adapted to be seated against theupper end of the hollow plunger 13. A threaded nut 24 is mounted on thelower end of the discharge tube 19 and a cap 25 onthe lower end of theintake tube 18, and when these two are tightened the head 21, plungerA13, retaining member 16, and the washer 17 will be securely clampedtogether for operation as a unit.

A feature of this invention resides in the novel means provided forlimiting the vupward movement of the-plunger, and such means referablyconsists in the provision of a suitable stop-provided adjacent the upperend portion of the cylinder. As shown 1n Figure 1, a packing nut 26 isprovided at the upper end of the cylinder and within this packing nutthe usual packing 27 is pro- `vided. An annular ring or detent 28 isseated against the end of the cylinder beneath the packing 27 and thisring over-- hangs the bore ofthe cylinder and thereby functions toprovide al limit stop. for the upward movement of the plunger. As shownin this figure, the major portion of the plunger 13 is preferablyreduced in diameter in order to provide an annular shoulder 29 adjacentthe lower end portion thereof. This shoulder isadapted to engage thestop ring 28 when the plunger reaches the limit of its upward movementas clearly shown in Figure 6. It will also be noted by referring toFigure 1 that means are provided for returning to the interior of theplunger 13 any oil which may-` pass by the packing cup 15 and enter theannular space around the plunger between the shoulder 29 and detent orstop ring 28, caused by the high pressure beneath the plunger when thejack is in op eration.y Such means preferably consists in providing aplurality of apertures 31 in the wall of the hollow plunger 13 slightlybelow the annular shoulder 29. grooves 32 in the outer wall of the pluner connect these apertures rwith the annu ar space around the plungerabove the shoulder 29, so that any oil, which might leak by the packingcup 15 from beneath the plunger 'and enter the annular space will bebypassed through the grooves 32 and apertures 3l into the interior ofthe plunger asit ascends, therebyeliminating the objectionable featureof the oil leaking out of the cylinder when the jack is used for liftingextremely heavy loads, which is a common occurrence with hydraulic jacksof ordinary construction. This, therefore, is an importantfea- Smallducts or j ture of the invention as it practically renders the jackleak-proof.

As shown in Figure 1, the intake tube 18 is provided with an intake port33l adjacent the lower end-portion thereof which is in communication,with the interior of the plunger 13. A valve 35 of'ordmary constructionarranged therein, is provided in the lifting head 21, and this portconnects the upper end of the intake tube 18 with a horizontal duct 36,having one end in communication with a similar upright port 37 whichdownwardl leads therefrom and is in connection wit the upper ,end of thedischarge tube 19. A

vspring-actuated check valve 38 is mounted 1n the horizontal duct 36,and this valve functions to prevent the oil pumped into the tube 19',from flowing `back into the intake tube 18 when the jack is beingoperated to lift a load. Threaded plugs 39 and 41 are mounted in thehead 21 and function to .close the ends ofthe port 34 and duct 36,

port 34 having a ball check respectively in order to facilitateassembling of the valves 35 and 38, mounted therein.

The means provided for by-passing the oil from beneath the plunger backinto the interior of the plunger, in the operation of lowering the jack,preferably consists in the provision of a tapered valve plug 42 seated ma correspondingly tapered `bore 43 provided in a boss 40 Ipreferablylintegrally formed on one side of the lifting head'21 as shown inFigures 1 and 3; This valve plug 42 also functions as a means for piv'otally connecting to the jack, the vjack handle and pumping means, whichwill subsequently be described. i Referring to the 'l above figures` itwill be noted that the horiannular groove 44 .provided in .the central-.portion of the'body of the tapered plug 42.

y -the tapered bore Lavamatv An aperture 45 is drilled through the plugin alinement with .the annular groove 44,

and this apertureis in communication with a conduit 46 provided shown inFigure 3. The other end of the conduit l46 terminates in a hub 47 whichis preferably integrally formed 0n the plug and is arranged at rightangles thereto. This hub is suitably threaded to receive one end of atube or pipe 48' `comprising the intermediate section ofthe handle. Thetapered plug 42 is yieldably retained in its tapered seat by means of acompression spring 49 coiled about the reduced end portion 5l thereof.has one end bearing against a w'asher 52 which is seated against theannular face 53 provided round the reduced end-portion of 43. Theother'end of the spring is seated in a cap 54 which is prevented fromoutward movement upon the reduced end portion 51 ofthe plug by means ofa pin 55. The reduced end portion 51 is preferably provided with aflattened surface 50as shown in Figure to prevent the cap 54 fromrotating thereon. The cap 54 is of such length as to normally be out ofengage- `ment with the face 53 and functions to provide a shield or.closure for the spring49 and washer 52 thereby to present a neaterappearance to the jack. The cap, however, may also function as a meansfor limiting the axial movement of the plug 42, should the pressurewithin the conduit 46 and groove 44 become so high that it would tend tounseat the plug from its tapered seat,as will hereinafter be more fullydescribed.

` Referring to Figure 9, it will be seen that the upright port 37 is incommunication with a relatively smaller'port 56 by meansvof a duct 57.The port 56 has onelend leading to the tapered bore 43 of the taperedplug 42. Similarly, the port 34 is connected to the tapered bore '43 bymeans of a duct 58 and a port 59 as shown in Figure 10. LThe ports 56and 59 are preferably horizontally in spaced parallel relation in thearranged lifting head 2l as particularly shown in Figure 4. In order tofacilitate construction the ports 56 and 59 are preferably drilled fromthe outside of the lifting head and it is therefore necessary that theirouter endsbe suitably sealed by such means as the threaded plugs 61. Inorder to establish communication betweenthe ports 56 and 59, a notch orrecess 62 is cut in one side.l of the tapered Yplug 42 in alinement withthe two ports, and when the plug 42 ispositioned as shown in Figure 4,communication between the twoports will be cut off, the `notch 62registering with the lower port 59 only. l/Vhen the jack is beingoperated to lift a load the tapered plug 42 will be positioned asshown'in Figure 4, and when it is de- A sired to lower the jack, theplug will be in the plug, as clearly This spring preferably i in thebpre o f the sleeve packing 69 is interposed, in the usual manrotated inits seat until the notch 62 is brought into registration with the twoports 56 and 59 there y .permitting the oil to flow from the uprightport 37 through the duct 57 ,port 56 and notch 62, port 59, duct 58,upright port 34, and through the intake pipe or tube 18 back to theinterior of the plunger. By this simple valve mechanism, therefore, theoperator will have complete control ofthe raising and lowering of thejack by simply rotating the plug42 in its seat.

Another feature of-this invention resides inthe novel means provided forpumping the oil from the interior of the vhollow plunger to beneath theplunger in-the lifting operation of the jack.l Such means prefer-v ablyconsists of'a reciprocating displacement pum mounted in a section of thehandle, whic handle is preferably composedof two sections in order thatit maybe conveniently foldedy for packing in a small place, and also forthe convenience in operation.- This pump consists of a pump-rod 63 whichis loosely fitted within a. hollow tube 64 as particularly shown inFigure 8. A knurled sleeve 65 is seycured to one end of the tube 64 bymeans of threads 66, and this sleeve is bored to receive a packing gland67 which has'provided thereon a shoulder 68 adapted to be seatedagainsta complementary shoulder provided 65. A suitable ner, between theupper end of the stationary gland 67 and the lower end of a movablegland 71 mounted in the enlarged bore 72 of the sleeve as shown inFigure l. The upper end of the sleeve is provided witha reduced endportion 73 which is threaded to receive a nut 74. This nut functions totightly force the movable gland 7 1 against the packing 69therebytightly compressing the packing against the pumpv rodl 63 A lock-spring7 5'is preferably interposed between'the vupper end of the reduced endportion 73 of the sleeve and the inner face of the'nut 74 andthis springfunctions to lock the nut in adjusted position. An op-l erating handleor grip 76 is secured to the lupper end of the pump rod 63 to provide Itwill also be noted by referring :to

Figures l Vand`8 that the pump rod 63 is loosely fitted within thevtherefore does not. come m contact with the hollow tube 64 and lthepump rod and the inner Wallof the tube allow the fluid to reely passthereby.

64 and this space is normally filled with the oil orother fluid used inthe operation of the jack. A vsmall head .-77 is preferably secured tothe lower end of the rod 63, this head merely functioning to prevent therod from being withdrawn from the tube 64. As shown in Figure 8, thehead 77 is preferably flattened on opposite sides in order to Ashereinbefore stated, the operating handle of this novel jack ispreferably con-w structed inV two sections, the pump section and anintermediate section connecting the pump section to the Lifting head ofth'e jack. The two handlesections are pivotally connected together bymeans'ofan oil-tight ljoint similar in construction to the tapered plugvalve connecting the intermediate han-- dle section to the lifting headof the jack as shown in Figure 3. This joint preferably comprises a'body 78 having a tapered `bore 79 provided therein adapted to receive acorrespondingly tapered plug 81 as shown in' Figure 2. The meansprovided for retainling the plug 81 in its seat is similar to, thatshown and described Iwith reference to thetapered plug '42, and likeparts will therefore be referred to by like numerals. Similar to'the plu42, the plug 81is provided with an annu ar groove 82 which is preferablyin alignment with the tube 64 of the pump section of the handle, whichtube is sey cured to the body 78 of the joint by means of the threads83. An aperture 84 is drilled ,through the plug 81 and this'apertureis'in vcommunication with a port 85 also provided in the plug and whichport terminates in a right-angled boss 86 threaded to receive one end-ofthe pipe 48 comprising the intermediate handle'section. By thusconstructing the handle'of two sections, the handle ma readily andconveniently be folded to 11e substantially arallel to the cylinder ofthe jack, there y permitting the jackto be packed away in` a smallspace, such for instance as the usual toolbox of an automobile or truck.When the jack is in use, the handle may be extended its fulllengtl1,-ther eby permitting the operator to stand in an erect positionwhen operating the jack, if he -de- A demountable lifting step 87 ispreferably provided aud this step has formed thereon an undercutl flange88 adapted 'to engage a similarundercut portion 89 of the lifting head21 when positioned thereon as shown inyFigure 1. A lug -91 is alsoprovided on the step 87 and this lug is adapted to engage the oppositeside of the head 21, thereby to securely lock `,the step to the lift.-

ingA head 21 when the step 87'is being used to lift the load. When thestep 87 is thus vwhen the oil is bein being used to lift a load, the lug91 bearing against the side of the liftin head 21, will be undercompression and t e upper portion 92 of the step will be under tensionas a result of the undercut flange 88 engaging the undercut portion 89of the head, thereby securely locking the step to'the lifting head ofthe jack. If desired, the lifting step 87 may be removed from the headof the jack by simply lifting the projecting lower end 87 thereof, andwhen thus removed the jack may be used without the vstep by placing thejack directly beneath the load and allowing the upper face of the head21 to contact therewith. A filler plug 93 isl provided in the head 2lthrough which oil may be introduced into the interior of the hollowplunger 13. i

In the operation of hydraulic jacks, itis necessary that means be.provided whereby. air may be admitted to the interior of the 'oilchamber or reservoir in order that the pump mayproperly function withoutthe danger of buildmg up avaculmior a high v pressure therein whichwould interfere with the operation of the jack and would tend to renderit inoperative. Means are therefore provided 'in this novel jack wherebyair maybe drawn into the hollow plunger 13 pumped therefrom into thecylinder 10 eneath the plunger.

Such means prefera ly consists in the ro` vision of an inclinedl'passage 94 provided in the lifting head 1 which establishescommunication between the interior of the hollow plunger 13 and thetapered seat 43 .of the lifting head. A,vent 95 is provided in the lowerwall of the hub 40 and this vent is in registration with a semi-annularroove 96 provided in one side of the tapere plug 42 as particularlyvshown in Figure 5. The passage 94, vent- 95 and the groove 96 are soarrangedas to be in alinement with one another, thereby providing acommunicating passage leading from the interior ofv the plunger 13 tothe exterior thereof. When the oil level in the hollow` plunger 13 islowered vbythe'pumping of theoil therefrom intothe lower portion of thecylinder beneath the plunger, air will be drawn into the plunger throughthe vent 95, therebyv preventing the, formation of a Vacuum with- 1n theupper end of the plungel, which would tend to rendery the jackinoperative. Conversely, when the oil is returned from the cylinder,beneath the plun er, back- 'to the interior of the plunger ro 13, theair drawn into the plunger above the oil level will be expelledtherefrom'through thepassage 94, groove 96, and vent '95 to the at`vmosphere.

In the operation. of this novel jack, the

plunger and cylinder thereof will first be A filled with a suitableliquid such as oil and the pump rod 63 reciprocated within the.

handle pipe section 64-until the oilvis drawn into the tube as shown inFigure 1, after which the jack is ready for service. lWhen and 5, inwhich position the port 6 v from the tapered bore 43 in the lifting headdesiring to lift a load.. the handle sections are extended or unfoldedto substantially a horizontal position as shownlin Figures 4 leading tothe upright port 37 will be closedl as par.- ti'cularlyshown in Figure4. thereby preventing the oil pumpedinto the lower portion of thecylinder from returning through the ports 56 and 59 to the interior 'ofthe plunger. As the pump rod 63 iswithdrawn from the tube or pipe 64,-oil will be drawn from the interior of the plunger through the port 33,intake t-ube 18,'port34, around the valve 35,l into the duct 36. throughthetavalve 38 after which it will be downwardlyy forced through theupright port 37 and intol the' discharge ipe 19 into the lower portionof the cy inder beneaththe plunger,

` from whence 5 5.

with the resultant raising of such plunger. Continued reciprocation ofthe pump rod 63` will cause the oil to be pumped from the interior'ofthe plunger tothe lower portion of the cylinder beneath the plungeruntil the load has been lifted to the desired height.

When itl is desired to lower' the jack, it is only necessary to slightlylower the intermediate handle section 48 from a'horizontal positionuntil the recess 62 in the plugl 42 is brought into registration withthe two ports 56 and 59, thereby establishing communication between thelower portion of the cylinder and the interior of the plunger.) Owing tothe high pressure of the oil beneath the plunger, caused by the loadresting thereon, the oil will be A'upwardly forced through the dischargepipe 19, and intoi the upright port 37, through the connecting duct 57,port 56, recess 62, port 59, connecting duet 58 and' into'the uprightport 34, it will flow downwardly through the intake pipe 18, through theport 33 and intothe; interior of the plunger, thereby allowingtheplunger, -and therefore Y the lifting head to descendtonormal orinoperative position. i

Referring toV Figure 4','it'will be noted that the connecting ducts 57and 58 are so arranged in the lifting head that the oil owing from thecylinder back to the interior of the plunger will not pass througheither ofthe valves 38 and 35. It will also be noted that the connectingduc-t 58 communicates withthe upright port 34 ata point below Another.

nection between the intermediate handle seetlon 48 and the lifting headof the jack which connect-ion serves av dual purpose. In addition 'toproviding a pivotal connection bet-ween the handle and the jack, it alsofunctions as a' safety valve, 'should the effective pressure `in thejack become excessive, as in the case the plunger has reached the top ofits stroke wlth the shoulder 29 abutting the stop ring 28 andtheoperator continues to manipulate the pump rod 63. Referring toeFigure 3it will be noted that a clearance is -provided between the face-53 oftheyboss 4() and the adjacent marginal.

edge ofthe cap 54, when the tapered plug 42.*is vin normal seatedposition asherev shown. "Thus, should, an excessiveI pressure be built'up in the plug 42, and therefore ,in the jack'and handle seotlions,such pressure will cause the tapered plug 42 to'be unseated or tobeaxially -moved in its tapered seator -bore 43 against the tension of thespring 49. Such axial' movement of the plug 42 'will allowa portion ofthe oil to-escape through the gap thus provided between the peripheralsurface of the plug and the wall of the tapered bore 43, therebyprotecting the jack against damage which might occur from excessive oilpressure.

From the foregoing, therefore, itv will be seen -that this novel jack issubstantially fool-proof. Its construction is such that it may `be lreadilyand conveniently operated also such that itV will be positive andeffi; cientin operation and erformance.` Having thus descri d ourinvention what we claim asnew and'desire to secure by Letters Patent,is: 1. A lifting jack 'comprising in combination, a cylinder, a hollowplunger therein, alifting head on the upper end of the the valve,thereby allowing the y -oil to enter the intake pipe 1 8 beneath thevalve 35, with the resultthat the valves re- 'main seated during thevlowering operation of the jack.

feature of this invention resides in-the'novel construction of thepivotal convfrom any posltion of the operator, and is plunger and thelowerplunge-end effecting 'l fluid-tight fit with the inner wall of thecylinder, an inelastic Huid within the plunger. pump means forforcingthe fluid from the interior of the plunger into a substantially4the lower portion of the cylinder beneath nular space between plungerand cylinder walls O'roovesf'n the enlarged wall ortion of theb plungercommunicating wit said annular space, and apertures connecting said thecylinder to the `grooves with the interior of the plun er', 'wherebyfluid escaping into .-the lannu ar space from beneath the plunger willbe returned to the interior of the plunger.

2. A lifting jack comprising in combinaf vvtion,`a cylinder. a hollowplunger therein,

a lifting head ou the upper endiof the plunger and the lower plunger-endeffecting asubstantially fluid-tight fit with the inner wall of thecylinder, an inelastic fluid within the plunger, pump means for forcingthe fluid from the interior of the plunger into ythe lower portion ofthe cylinder beneath.

' the plunger to 'raise it, means for lay-passing the. fluidfrom thecylinder to the interior of the plunger to lower the latter` a portionof the plunger wall being reduced eX-' teriorly thereof to provide anannular space between plunger and cylinder walls, grooves ing into theannular space from-beneath the plunger will be returned to the interiorof the plunger, an annular` shoulder on the plunger wall exteriorlythereof 'and adjacent to its lower end, an abutmentring demount'a-blyseated upon the upper end of the cylinder and'overhanging the borethereof,

tion, a cylinder, a hollow plunger operable therein, a lifting head onthe upper end of the. plunger and tlie'lower lplunger-end effecting asubstantially fluid-tight fitwith the inner wall of thecylinder, aninelastic fluid within the plunger,y means to pump the fluid from theplunger and force it into the lower portion`of the cylinder beneath theplunger to raise it, means for returning t-he fluid from the cylinder tothe interior of the plunger to lowerthe latter` stop means on theexterior of the plunger to limit its raising, the exterior of theplunger Wall having y, a duct therein communica-ting with an aper-l turetlirou h said wall whereby any fluid escaping a ove the lowerplunger-end returns to. the plunger interior`l said aperture beinglocated below saidI stop means.

' In witness whereof, we have hereunto Set our hands this 23rd Iday ofMay 1924.

- TIMOTHY C. POB/LEROY.l

CARL E. JOHNSON.

